The present invention relates to a clipping device for performing an operation, such as stopping bleeding, in living tissue with the use of a clip.
The clipping device disclosed in Jpn. Pat. Appln. KOKAI Publication No. 8-280701 has an operation tube slidably located into an insertion tube and a coupling ring fixedly mounted on the distal end of the operation tube to hold a clip unit in place. In this publication, a hook member is connected to the distal end of an operation wire inserted into the operation tube and the clip unit is detachably latched to the hook member. Since, in this clipping device, the clip unit was detachably mounted on a device body, it was necessary to perform an operation of mounting the clip unit to the hook member of the device body each time the clip was used. The clip unit itself was very small in size and it was cumbersome to latch a coupling plate of the clip unit to the hook member fixed to the distal end of the operation wire. The mounting operation of the clip unit was cumbersome and it took a lot of time to prepare the clipping device for actual use.
Further, after the clipping, the coupling member separated from the clip was sometimes dropped in the body cavity. When the coupling member was dropped in the body cavity, it was necessary to perform an operation such as removing it to an outside. However, the coupling member itself was very small, thus making it difficult to find. In addition, the removal operation was also cumbersome. These operations took a long time to perform, thus placing a greater burden was placed on the patient.
After the clipping operation, the clip is separated from the coupling member by strongly pulling the operation wire. At this time, by exerting a strong pull force exceeding a given force on the operation wire, the hook section of the coupling plate of the clip unit is elongated to a full extent and the clip is separated by doing so. Since the clip is separated from the rest of the device with the hook section of the coupling plate elongated to the full extent, if a pull force on the hook section is released the instant the clip is separated off the coupling plate, then the operation wire on which such a strong pull force has thus far been exerted is drawn into the coil sheath and also the hook member is drawn deep into the coil sheath. If the hook member is so drawn deep into the coil sheath, then it takes a long time to mount a new clip unit on the rest of the device.
The hook member fixed to the distal end of the operation wire is usually made of a rigid member so as to secure its strength. For this reason, the length of the rigid section area near that distal end is made longer by the amount of the rigid member and the insertion operation into the endoscope becomes more cumbersome with a resultant disadvantage.
As endoscopes, the so-called side viewing and oblique viewing scope are known and, in these types, the clipping device is projected in a side or oblique direction from such a type of endoscope. If, therefore, the length of the rigid section area near the distal end section is made greater, the insertion operation into the endoscope becomes much more cumbersome.
Further, where the clipping device is used in combination with the side viewing and oblique viewing scopes, the coil sheath into which the hook member is drawn is tightly bent, so that the hook member is liable to be deformed when it is drawn into the coil sheath. When the hook member is so deformed, then it becomes difficult to mount a new clip on the device body. It has, therefore, been considered difficult to use the clipping device in combination with side viewing and oblique viewing scopes.
Further, the coupling method of the clip and device body poses a problem such as the dropping of the clip out of the device body due to vibration or drop page during a transport, etc. At this time, it is necessary to perform an operation such as, again, mounting the clip on the device body.